A new view of photoreceptors

for stratification in the Southern Ocean and the resulting strength of the Antarctic Circumpolar Current (in which it is generally thought that eddy fluxes are indeed a significant factor). Moreover, predictions for other ocean basins give reasonable thermocline structures, hinting that this concept has much wider applicability than in just the Southern Ocean, and that a complete thermocline theory must consider the role of eddies. It is early days for an idea that has not yet been adapted to realistic ocean conditions. But the first signs are encouraging: it may be large, horizontal eddies — rather than small, vertical ones — that control the ocean. ■ Chris W. Hughes is at the Proudman Oceanographic Laboratory, Bidston Observatory, Prenton, Merseyside CH43 7RA, UK. e-mail: [email protected]